You don't need to clean before the cleaners come. You do get more out of the visit when surfaces are reachable, so a quick pick-up of clothes, toys, mail, and dishes lets the team get straight to the work you're paying for.
Tell us about anything that needs special care: antique furniture, a stone countertop that needs a specific product, a surface that shouldn't get wet, or a room that's off limits. We note it on your checklist so it's handled the same way on every visit.
Pets are welcome, and it helps to know their names and whether they're comfortable with visitors. If a dog is nervous around vacuums, a closed door or a crate for the hour makes the visit easier on everyone.
Let us know how to get in and how you'd like us to lock up. Many clients use a lockbox or garage code; others prefer to be home for the first visit and hand off a key after that. Either way works, and it's set up once, not every time.
Finally, walk the house after the first clean if you can. The first visit is where we learn your home, and five minutes of feedback then saves a lot of guessing later.